Method of making printing plates



P 1937. w. s. LENNOX 2,092,979

METHOD OF MAKING PRINTING PLATES Filea March 16, 1936 FIG.1. FIG.2. FIG.3.

FIG. 4.

INVENTOR Walter S. Lennox ATTORN EY Patented Sept. 14, 1937 UNlTED sTA'rs METHOD or MAKING PRINTING- PLAT'EIIS. J Walter S. Lennox, Rochester, N. Y., assignor to Rochester Electrctype Company, Inc., Rochester, N. Y., a. corporation of New York Application March 16, 1936, Serial No."69,123 H 11* Claims. o1.1o1+401.2)

This invention relates to a method of making printing plates, such as photo-engravings-, zinc etchings, electrotypes, or the like, and has-for its object to afford a procedure 'thatwill insure 5' accurate registering of each plate in a press, Where several plates are used on the same job, as

in multi-color work, and thereby to'prevent. over-'- lapping 'or improper registration of one impres-s sion with relation to another.

10 Various methods and devices have been unsuccessfully tried for accomplishing this purpose,

and it is the object of this invention to afiord a method that makes it'possible to produce such printing plates in a practical and economical way, and'which facilitates accurately positioning the plates in a press, thus efiecting a material savingof time as compared with practices heretofore followed which require considerable'time for the operator in positioning the plates accurately to obtain the necessary correct registry.

In a more particular aspect, the invention C011? sists in forming on each photo-engraving, zinc etching, electrotype or stereoty'pe'of a series, a

plurality of projections, produced photographically from the original drawing from which the several plates are made, and utilizing these pro-' jections to locate the plate in a jig or device in which suitable registering devices are formed on the plate. The projections being produced photographically on the several plates from a common drawing all possess the same relation to the printing surfaces on the plates, and by utilizing these projections to locate the plate in the jig, the pro- 35 jections or positioning means can be formed accurately at the same relative position on each plate, andby this procedure, correct registry of the several plates is insured when they are positioned inthe press.

40 To these and other ends, the invention comprises the method that will. appear clearly from the-following description when read in conjunction with the accompanying drawing, the novel features being pointed out in the claims follow- 45 ingthespecification. .1

In the drawing:

Fig. 1 is a. plan viewof a drawing made in accordance with. one embodiment of the invention, and from which the photo-engravings or zinc 50 etchings are made photographically, and electrotypes or stereotypes made subsequently;

. Fig. 2is a similar view of one electrotype or stereotype thus produced, for printing a part of the subject matter in one-color;

Fig. 3 is a similar view of a second electrotype or stereotype for. printing another partof the same subject matter in another color; Fig.4 isa transverse sectional view on line 4 -.4 ofFig.3;, 1 Fig. 5 is a-perspective View of asuitable jig, or device employeclhforforming the. openings or other registering means in the electrotype ,or printing plate; I 1 t Fig. 6 is a transversesectional viewv through the, jig, showinga printingplate positioned and 10 clamped therein, and readyto have the registeringopenings formed in it; t

Fig, 7 isa perspective .viewof a suitable base for a printing press showing registering pegs or projections to receive the printing platekands v Fig. 8. is a transverse sectionallviewjshowing a printing pI-atepositioned on a basei The invention may be carried outina variety of ways, and for purpose of illustration 1' have shown in Fig. 1 an original drawing of, the sub- .20 ject matter to be printed,,surrounded; by a marginal line I which may be drawn at the time the artist makes the original drawing, or the marginal line I may be previously positioned on the drawing paper byphotographic processes'or otherwise. The marginal line constitutes the meansfor producing the positioning or projecting portions on the printing plate that is produced therefrom photographically, and while -I have illustrated the line'l as extending entirely around the drawing and forming 'a'complete margin, the results may be accomplished by portions of a line, or by marginally arranged dotsor dashes, or other indications extending around the sheet and meeting at the corners, that will. function the same as a. marginal line when reproduced on the printing plate to locate the latter along two directions in the jig. I

After the completion of the drawing, as shown in Fig. 1, photo-engravings or 'zinc' etchings are,. made therefrom by usual photographic processes which are well known in the art and require no detailed explanation, and from the photo-engravings, electrotypes or stereotypes such as shown in Figs. 2 and S'may be made by conventional meth- .45 ods, the printing operation being effected. by the" electrotype, or by the zinc etching, when suitably located in a press.

It will be understood that the marginal: line i is reproduced on the photo-engravings; zincl etchings, electrotypes, or stereotypesas indicated at 2, being in the form of portionslth'at project away from the printing plate similarlyto-the printing surfaces; 3, the projecting portions 2 l being employed to'locate thexprinting, plate:;iin,. 5

a jig or other suitable device while forming the registering means, preferably in the formI of openings, in the back of the printing plate.

A jig or device suitable for doing this work is shown in Fig. 5, and includes a base 4, having legs 5, and provided with openings 6 extending therethrough to admit a drill or suitable tool employed to form the registering openings in the back of the printing plate. The base 4 is also provided with lugs I to which is pivoted a cover plate 8, the latter being bifurcated at 9 to receive a clamping bolt I0. Mounted upon the base 4 are guides H arranged at right angles to each other for cooperation with an end and side of the printing plate. These guides are stationarily positioned on the base 4 and include overhanging portions l2 adapted to overlie the edge of the printing plate. I3 is an adjustable guide mounted on the base 4 and pro 'ded with slots l4 and adapted to be held in place by the screws l5, the guide l3 also including an overhanging portion l6.

The electrotype or printing plate is positioned in the jig by placing it with its back face against the base 4 and sliding its edges under the overhanging portions l2 until the outer surfaces of the projecting portions 2 along one side and one end of the printing plate are in close engagement with the cooperating overhanging portions 12. The guide l3 is then moved laterally into contact with the printing plate and the screws l5 tightened so as to hold the printing plate tightly in the jig in correct position, as determined by the overhanging portions l2 engaging against the projecting portions 2 on the printing plate, which thus serve to locate the latter in the jig. The cover plate 8 is then swung downwardly and clamped into position, the jig reversed as shown in Fig. 6, and registering means, preferably consisting of holes formed in the back face of the printing plate by drills or other suitable tools operating through the openings 6. After the registering openings are formed in the printing plate, the projecting portions or margin 2 is 45 preferably cut away or otherwise removed from the printing plate before placing it in the press.

The press in which the plates are used is provided with a base or bases H, see Fig. '7, in which a series of properly located registering pegs or projections l8 are secured to engage with the registering openings in the printing plate or plates, and when the operator positions the plate or plates on the base or bases: of the printing press, it is necessary only to bring the openings 55 IS in the back of the plate or plates into engagement with the registering pins l8, no further adjustment of the plates being required.

Since the several plates of a given series are all similarly positioned in the jig when the registering openings l9 are formed, and are located in the jig by the marginal projecting portions 2 which are photographically produced from a common drawing and therefore in the same predetermined relation to the printing surfaces on each plate, there is no chance of error, and correct registry of the different components of a multiple-impression printing operation is insured.

While the invention has been described with reference to a certain procedure, it is not confined to the precise steps herein disclosed, and this application is intendedto cover any other methods or departures from the process herein set forth that may come within the intent of the invention or the scope of the following claims.

I claim:

1. The method which consists in forming a printing plate with projecting positioning portions in the form of perpendicular lines outside the printing surfaces, locating said positioning portions against a pair of perpendicular guide members in a jig, providing the plate with registering means while located in the jig, and thereafter removing said projecting portions from the plate.

2. The method of making a plurality of printing plates which consists in providing each plate with projecting positioning portions in the form of perpendicular lines in predetermined relationship'to the printing surfaces, locating said positioning portions against a pair of perpendicular guide members in a jig, forming registering means on the plate while located in the jig, and thereafter removing said positioning portions from the plate.

3. The methodof making a plurality of printing plates which consists in forming an angular marginal projection on each plate in predetermined relation to the printing surfaces, positioning said angular projection against a pair of intersecting guide members in a jig, forming registering means on the plate while located in the jig, and thereafter removing said marginal projection from the plate.

4. The method of making a plurality of printing plates which consists in making a drawing of the matter, to be printed within a marginal line, producing a plurality of photo-engravings and electrotypes from said drawing, said marginal line affording a marginal projection on each electrotype, positioning said marginal projection against a pair of intersecting guide members in a jig, forming registering means on the electrotype while sopositioned in the jig, and thereafter removing the marginal projection from the electrotype.

5. The method of making a printing plate which consists in forming a plurality of perpendicular straight projections thereon by a photographic method from a drawing, positioning said projections against a pair of intersecting guide members in a jig While forming registering mean thereon, and thereafter removing the projections from the plate. I

6. The method of making a printing plate which consists in forming the same with a straight projecting margin by a photographic process from a drawing containing a marginal line, positioning said projecting margin against a pair of intersecting guide members in a jig, forming registering means on the plate while so positioned, and thereafter removing the projecting margin from the plate.

'7. The method of making a printing plate which consists in forming the same by a photographic process with straight, perpendicular positioning projections located outside the printing surfaces, and locating said positioning projections against a pair of intersecting guide members in a jig while forming registering openings in the plate.

8. The method of making a printing plate which consists in forming the same by a photographic process with straight, perpendicular positioning projections located outside the printing surfaces, locating said positioning projections against a pair of intersecting guide members in a jig while forming registering openings in the from the plate.

9. The method which consists in making a tioning projections outside the printing surfaces,

making an electrotype therefrom, and locating 5 the outer surfaces of said on the electrotype against guide members in a, jig ing openings in the elect positioning projections a pair of intersecting while forming registerrotype.

10. The method which consists in making a 1 photo-engraving with straight, perpendicular p0- sitioning projections outsi de the printing surfaces,

making an electrotype therefrom, locating the outer surfaces of said positioning projections on the electrotype against 15 guide members in a jig w a pair of intersecting hile forming registering openings in the electrotype, and thereafter removing the projections from the plate.

11. The method of making a plurality'of print-' ing plates which consists in first forming perpendicular marginal lines on a sheet of paper, making a drawing of the matter to be printed within said marginal lines, producing a plurality of photoengravings and electrotypes from said drawing, locating each electrotype in a jig by positioning with the outer surfaces of said perpendicular marginal lines against a pair. of perpendicular guide members, and thereafter forming registering means on the electrotype while so positioned in the jig.

- WALTER S. LENNOX. 

